First Drive: Audi S7 & S6

Our 2012 Automobile of the Year — the swift, elegant, and luxurious Audi A7 — has the perfect engine for the times. The supercharged V-6 gracefully merges performance and efficiency, with its 5.0-second 0-60 mph time and 28-mpg highway fuel economy. Yet a luxury sedan of this caliber also makes a natural host for a V-8, a fact that we acknowledged in our story when we wrote, “A dealer friend of ours tells us that some customers are skeptical of the A7 because it doesn’t have a V-8. They shouldn’t be. The muscular six makes this sleek Audi as fast as it appears.”

Maybe you want an A7 that’s faster than it looks. For you, Audi has transformed the A7 into the quicker, sportier 2013 Audi S7 with an eight-cylinder engine, a new transmission, and an air suspension. Building on the rock-solid foundation of the A7, the S7 is even more rewarding to drive hard thanks to quicker acceleration, sharper shifts, and flatter handling.

We drove the new S7 in Munich, Germany, back-to-back with the 2013 Audi S6. Mechanically, the two cars are identical, but the S6 replaces the S7’s sloping roof and rear hatch with a traditional sedan profile and trunk. The S6 is also 110 pounds lighter and about $8000 cheaper than the S7. Any differences in driving behavior, though, are so insignificant that they’re indiscernible. So while this review is written from the perspective of the S7’s driver’s seat, impressions carry over to the S6.

The heart of the S7 is a twin-turbo, 4.0-liter V-8 that makes 420 hp and 406 lb-ft of torque, up from 310 hp and 325 lb-ft of torque in the A7. The eight-cylinder makes for visceral acceleration, but the S7 is very much a well-mannered beast with a muted growl, linear power delivery, and supreme smoothness. Standard all-wheel drive removes all the drama from a stoplight sprint and the overall refinement is right in line with that of the A7. Audi claims a 0-60-mph time of 4.6 seconds (the lighter S6 will do the sprint 0.1 second quicker), which is a quantifiable improvement, but it’s not so significant as to cause us to back down from what we wrote about the A7: its supercharged V-6 is a fantastic engine that will suit most buyers.

The S7’s powerplant is essentially the same engine found in the larger Audi S8 and the Bentley Continental GT V8, but in those cars the twin-turbo V-8 produces 520 hp and 479 lb-ft. The power difference isn’t just a matter of software tuning; there are hardware differences as well. The S8 has separate air intakes for each cylinder bank, while the S7 has a single intake feeding all eight cylinders. The V-8’s accessory belt spins a hydraulic steering pump in the S8, but the S7 uses an electric assist motor mounted on the steering rack. The different variants also use unique pistons, and the S8 engine has an oil cooler that the S7 doesn’t. Like the S8, though, the S7 can run on just four cylinders during mid-speed, light-load cruising in order to save fuel.

Why did Audi leave 100 hp on the table? For an RS7 and RS6, of course. Even though Audi hasn’t confirmed those cars, we’re confident they’re coming. Just as much as we want them, Audi needs them to neutralize the misguided people that will compare the S7 to the BMW M5 and the Mercedes-Benz CLS63 AMG. The S7’s real bogies are the BMW 550i xDrive and the Mercedes-Benz CLS550 — in price and performance.

Still, it’s important to note that Audi aimed for a sportier driving experience than those competitors. A key player in that pursuit is the seven-speed dual clutch automatic that replaces the A7’s eight-speed automatic. The eight-speed is a fast and fluid gearbox, but the S tronic transmission is even quicker and in dynamic mode it delivers a sporty kick with every gear change. At a slower pace, though, the transmission is sometimes reluctant to downshift and the subtle pulse that accompanies every gear change is occasionally — rarely — a big thud. All in all, though, the dual-clutch transmission is a welcome addition that raises the level of driver engagement.

It’s also refreshing to see that Audi of America is learning just how we like our cars. The variable ratio steering that’s optional in Europe won’t be offered in the States, while the torque-vectoring sport differential will be standard equipment. Both of those decisions are in the best interest of people who drive quickly. Dynamic steering has an unpredictable variable ratio and the sport differential erases understeer from near-the-limit driving by sending power to the outside rear wheel in a turn. The S7’s standard air suspension makes for a 0.4-inch lower ride height than the A7 in its normal setting. At highway speeds or when Audi’s Drive Select is set to “dynamic” mode, the ride drops another 0.4 inch. Although comfort, auto, and dynamic modes each have a different stiffness, the S7 always relays a controlled, confident ride without ever being punishing. On gently flowing German backroads, the S7 changes directions with the feel of a much smaller and lighter car thanks to the impressive grip and the nicely calibrated electric power steering.

For anyone who’s driven an A7, piloting the S7 will be a familiar exercise. Luxury, performance, and style — the S7 delivers everything the A7 does, only with a sportier edge. We’re still smitten with the less powerful, more efficient supercharged V-6 in the A7, but the twin-turbo V-8 is similarly sweet for those who demand more. With the S7, Audi has taken one of the best cars on sale today and made it even better.

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